Pharmacogenetic analysis of the pregnane x receptor in breast cancer. Case-control study

Dissertação de Mestrado, Mestrado em Qualidade em Análises, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Genetic considerations on the introduction of farmed fish in marine protected areas: The case of study of white seabream restocking in the Gulf of Castellammare (Southern Tyrrhenian Sea)

Human exploitation has drastically reduced the abundance and distribution of several marine fish and invertebrate populations through overfishing and habitat destruction. Restocking can potentially mitigate these impacts and help to reconstitute depleted stocks but genetic repercussions must be considered. In the present study, the degree of genetic similarity between white seabream (Diplodus sargus Linnaeus 1758) individuals reared for restocking purposes and the receiving population in the Gulf of Castellammare fishery reserve (Sicily, Italy) was assessed using microsatellites. We also inferred the spatial pattern of the genetic structure of D. sargus and connectivity along Sicilian coasts. The farmed population showed significant heterozygosity deficiency in 6 loci and an important reduction in the number of alleles, which could indicate an incipient inbreeding. Both the farmed population and the target one for restocking (Castellammare fishery reserve), showed high and significant values of genetic differentiation due to different allele frequencies, number of privative alleles and total number of alleles. These findings indicate a low degree of genetic similarity between both populations, therefore this restocking initiative is not advisable. The genetic connectivity pattern, highly consistent with oceanographic currents, identified two distinct metapopulations of white seabream around Sicily. Thus it is recommended to utilize broods from the same metapopulation for restocking purposes to provide a better genetic match to the wild populations.

The role of hypoxia in the regulation of membrane transporters

ATP binding cassette (ABC) and solute carrier (SLC) transporters are responsible for the majority of the transcellular movement of various substrates, including drugs, among epithelial cells. Despite the well characterized regulation of influx (SLC) and efflux (ABC) transporters by endogenous mediators, such as inflammatory cytokines, little is known about how changes in oxygen levels may affect expression of these transporters. In this study we showed that the expression of SLC22A4, SLC22A5, SLC22A1, SLC02B1, SLC10A2, ABCC2 and ABCC3 transporters is upregulated by hypoxia in HT29 colon carcinoma cells, but not in HepG2 hepatocarcinoma cells. Moreover, OCTN1 (SLC22A4), OCT1 (SLC22A1) and OATP-B (SLC02B1) transporter expression is also induced by inflammatory cytokines but in a smaller extent than in hypoxia. Furthermore our experiments indicate that there is no cross talk between HIF-1 and NF-κB pathways in HT-29 cells, but these two pathways act simultaneously activating common genes, such as, some SLC and ABC transporters. Our preliminary results from studies with an in vivo murine model of colitis, suggest that HIF-1is stabilized and OCTN1 is strongly induced during severe inflammation, which can be relevant for a recovery from the inflammatory process. We have also been interested in the distribution of HIF-1α variants among different ethnic groups as well as their contribution for cancer risk. Thus, we have demonstrated that there is an ethnicity-related variation in the frequency of the C1772T (P582S) single nucleotide polymorphism (SNP) in the HIF-1α gene. Furthermore, we performed a case-control study in a breast cancer population and our results suggest that there is no association between this SNP or the rare G1790A (A588T) SNP and the incidence of breast cancer. Taken together, the results obtained in this study contribute to a better knowledge of drug influx and efflux during hypoxia and inflammation as well as to the understanding of the pharmacogenetic variability of the HIF-1.